Vaccine Development and Manufacture

What Are Vaccines?

When you get sick, special proteins (antibodies) are produced by your immune system to fight off the virus. After your immune system has fought off the virus once, you rarely, if ever, contract that virus again. This is because there are memory cells in your immune system that are used to remember what specific antibodies were used to fight off the sickness, so if you are ever exposed to that same sickness in the future, your body can fight it off easily without feeling the symptoms.

But what about life-threatening viruses? Our natural immune system can only go so far. This is why we need vaccines. Vaccines are used to activate an immune response from the body, without ever actually getting you sick! You may be wondering how this is possible. Vaccines are made using the weak or even dead strain of the virus to produce a reaction without getting the symptoms.  Vaccines can help prevent or completely eliminate the possibility of contracting a life-threatening virus or disease.

Weak vs. Dead Strain Vaccines

Weak strain vaccines are created by reducing the virus’ capability to multiply in the body. By preventing the virus from multiplying too many times, immunity is developed in the body without contracting the actual disease. Some may be hesitant to take a vaccine with a mildly active virus, even if it is an extremely weak strain, but it is actually the more effective type of vaccination. Because the virus is still mildly active (though, again, heavily weakened), the body forms a long-lasting immunity with very few follow-ups (the need for more than one vaccine application).

In order to create a dead strain vaccine, a virus must first be killed with chemicals. This completely inactive strain would then be introduced to the body. Because the virus strain would be unable to replicate itself, there would be absolutely no chance of the disease being contracted. Protection from the virus in question would be developed without experiencing any symptoms. However, this type of vaccine is not as effective as the weakened strain vaccine and only produces relatively short-term protection. The vaccine would have to be given periodically to develop longer lasting immunity.

http://www.chop.edu/service/vaccine-education-center/vaccine-science/how-are-vaccines-made.html